Control device



July 14, 1959 B. H. SHORT 2,895,090

CONTROL DEVICE Filed June 15, 1956 v --..I H 2s so 36 32 F g. 2

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INVENTOR. Brooks H. Short His Attorney 2,895,090 Patented July '14, 1959 CONTROL DEVICE Brooks H. Short, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 15, 1956, Serial No. 591,709

8 Claims. (Cl. 317-188) This invention relates to control devices and more particularly to a solenoid type actuating device which will move and position an element in any one of three positions.

One of the objects of the present invention is to provide a control device wherein an actuating member is magnetically moved and positively positioned in any one of three positions.

Another object of the present invention is to provide a solenoid with a pair of individually energizable mag netic coils and stop means so the solenoid plunger will be moved and positively maintained in any one of three diiierent positions when the coils are selectively and individually energized.

A further object of the present invention is to provide a magnetically actuated device with three individual stop means and a pair of individually energizable magnetic coil windings so a plunger may be moved when either of the coil windings is energized from one predetermined position to either one of two other predetermined positions whereat the magnetic attraction of the coil windings to maintain the plunger in said positions will be at a maximum.

A still further object of the present invention is to provide a magnetically actuated device with: a pair of axially spaced and individually energizable coil windings, a plunger with an armature slidably mounted thereon and a pair of springs, and to arrange said springs so one of the springs opposes the movement of the plunger and the other opposes movement of the armature on the plunger. Thus, when neither of the coils is energized, the plunger and armature will be in one predetermined position, when one of the coils is energized the plunger will be moved to 'a second predetermined position and when the first energized coil is de-energized and the second coil is energized the plunger is moved to a third positive position.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 partly in section shows the device according to the present invention with the parts thereof in one position.

Fig. 2 shows the device in Fig. 1 with the parts moved to a second position.

Fig. 3 shows the device in Fig. 1 with the parts in a third position.

In the drawings the electromagnetic control device 20 shown may be used with a valve, a switch or any other suitable device which has an element requiring movement to any one of three positive positions.

The electromagnetic device 20 includes a pair of coil windings 22 and 24 which are maintained in tandem as shown in the drawings by a shell 26. These coil windings 22 and 24 are each formed with a bore extending therethrough and are longitudinally spaced by the wall 30 which preferably is formed of magnetic material as part of shell 26. The wall 30 has an aperture 32 preferably of the same diameter as bore 34 which is provided when the windings 22 and 24 are axially aligned in shell 26. The bore 34 has an open end 36. The other end of bore 34 is closed by a wall 33 which is formed to include a pole piece 28. A plunger 38, which will be later described, is movable in bore 34. This plunger 38 is sized so a minimum air gap will be present between the outer walls of the plunger and the wall portions which define opening 32. The wall 33 is preferably threaded into the shell 26. This arrangement will permit the coil winding 24 to be inserted into shell 26 against wall 30. The end of shell 26 adjacent the open end 36 of bore 34 is preferably turned or spun over as shown after coil winding 22 is in position in shell 26 against wall 30. This turned over portion 40 is preferably sized to provide a relatively large air gap between the plunger 38 and the material of the shell 26 which forms the portion 40.

The plunger 38 preferably has a cone-shaped inner end 42 which is complementary in shape to the pole piece 28. The other end of the plunger 38 preferably has its diameter reduced to provide a portion 44 which is separated from the portion '46 of the plunger 38 by a shoulder 48. An armature 50 which is slidably mounted on portion 44 of the plunger is constantly urged into engagement with shoulder 48 by a spring 52. The spring 52 has one of its ends seated against the armature 50 and its other end resting on a spring seat 54 which is innnovable on plunger portion 44.

The armature 50, spring 52 and spring seat 54 are enclosed by a cup-shaped cover 56. This cover 56, which has its rim resting on shell 26, has an opening through which the plunger portion 44 extends. The plunger 38 and armature 50 as it rests on shoulder 48 are both urged to the left in the drawings by a coil spring 58. This spring 58 surrounds the portion of the plunger portion 44- which extends exterior to cover 56 and has one end seated on the cover and the other end seated on a spring seat 60 which is immovable on plunger portion 44.

With the above parts of the device in mind its operation will now be described. In Fig. l of the drawings, the parts of the device are shown in the at-rest position, that is, when neither of the coils 22 and 24 is energized. When this condition exists, the spring 58 will cause the armature 50 and the plunger 38 to be moved to the left until the spring seat 54 engages the cup member 56 to hold the plunger in a positive predetermined position.

The magnetic flux generated when coil 22 is energized, will attract the armature 50. This flux will cause the armature to move to the right into engagement with por tions 4% of shell 26. The movement of the armature 50 will be transmitted through shoulder 48 to plunger 38 to cause the plunger to move to the right to the second positive position which is dictated when the armature 50 engages the shell 26. This is shown in Fig. 2. When the parts are in this position the majority of the magnetic flux which is set up by coil winding 22 will flow in a magnetic circuit which includes the wall 30, the outer portions of the shell 26, the inwardly turned portions 40, the armature 50 and the plunger 33. As heretotore stated the air gap between the portions 40 and the plunger is large and the air gap between the walls 30 and the plunger is preferably of a small magnitude. Thus, the majority of the flux instead of passing through the large air gap will pass through the armature. This means the coil winding 22 will exert its maximum holding force on the armature 50 when the parts are in the position shown in Fig. 2. When the parts are in Fig. 2 the spring 52 is not compressed, for the magnetic attraction of coil Winding 22. on the plunger is negligible. When the parts are moved to the position shown in Fig. 2, spring 3 SS is only partially compressed as further movement to the right of the plunger is limited by the engagement between the armature 50 and shell 26.

The movement of the parts of the device to the position shown in Fig. 3 is accomplished when coil 22 is deenergized and coil 24 is energized. When coil 24 is energized, the magnetic flux circuit established attracts the portion 46 of the plunger to move the plunger 38 to the right where it engages the end piece 28. Again the flux circuit set up by the energized coil 24 will exert its maximum attraction on the plunger 33, for substantially all of the flux which passes through the plunger 38 will pass through the cone shaped end 42 and the pole piece 28 when the plunger is in engagement therewith. When coil 24 is energized, springs 58 and 52 will be 'fully compressed as shown and the plunger 38 will be held in its third positive position as shown in Fig. 3 against further movement by its engagement with end piece 28.

In the embodiment of the present invention as described, core winding 22 was first energized to move the plunger 38 from the position shown in Fig. l to the position shown in Fig. 2. This was described as occurring before coil winding 24, was energized to move the plunger from the position in Pig. 2 to the position shown in Fig. 3. Obviously, if desired, the plunger may be moved directly from the position shown in Fig. l to the position shown in Fig. 3. This may be accomplished by energizing coil Winding 24 without first energizing coil winding 22.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. in a device of the character described, the combination comprising; a pair of individually energizable coil windings axially aligned and arranged to provide a central bore having an open and closed end, a plunger slidable in said bore and movable therein by magnetic attraction when either of said coils is energized, an armature slidably mounted on said plunger and arranged to .iove said plunger a predetermined distance in a first direction to a predetermined position when only one of said coils is energized, first spring means between said armature and plunger arranged to oppose the movement of said plunger in said first direction from said first predetermined position to a second predetermined position where the plunger engages the closed end of said bore and the other coil is energized, and second spring means between said plunger and an enclosure for said coils arranged to move said plunger and armature in an opposite direction from said first direction to a third positive position when neither of the coils is energized.

2. In a device of the character described, the combination comprising; a pair of individually energizable coil windings axially aligned and arranged to provide a bore having an open and closed end, a plunger movable by magnetic attraction in said bore in a first direction when either of said coil windings is energized, an armature slidable on said plunger and arranged to move said plunger in said bore in said first direction when only one of said coil windings is energized, a compression spring interposed between said armature and plunger opposing movement of said plunger in said first direction, a second compression spring interposed between said plunger and a member fixed with respect to said coil windings opposing movement of said plunger in said first direction, said second spring being arranged to maintain said plunger in one position when neither of said coils is energized, said first mentioned spring being arranged to maintain said plunger in a second predetermined position when.

said one coil winding is energized and said closed end being arranged to maintain said plunger in a third predetermined position when said other coil is energized.

3. in a device of the character described, the combination comprising; a pair of individually energizable coil windings axially aligned and arranged to provide a bore having an open and closed end, a plunger movable by magnetic attraction in said bore in a first direction when either of said coil windings is energized, an armature slidable on said plunger and arranged to move said plunger in said bore in said first direction when only one of said coil windings is energized, a compression spring interposed between said armature and plunger opposing movement of said plunger in said first direction, a second compression spring interposed between said plunger and a member fixed with respect to said coil windings opposing movement of said plunger in said first direction, said second spring being arranged to maintain said plunger in one position when neither of said coils is energized, said first mentioned spring being arranged to maintain said plunger in a second predetermined position when said one coil winding is energized and said closed end being arranged to maintain said plunger in a third predetermined position when said other coil is energized, said coils, armature and plunger being constructed and arranged so the coils will exert a maximum magnetic attraction when the plunger is at said second and third positions.

4. In a device of the character described, the commination comprising; a pair of individually energizable coil windings, one of which has a bore extending therethrough and the other has a bore with a closed end, said coil windings being axially aligned to provide a bore with a closed and open end, a plunger movable by magnetic attraction in said bore in a first direction when either of said coil windings is energized and arranged to engage the closed end of said bore and position said plunger in said bore when said other coil is energized, an armature slidable on said plunger and arranged to move and position said plunger in said bore when said one coil is energized, and a means for opposing the movement of said plunger in said bore in said first direction and for positioning said plunger and armature when neither of said coils are energized.

5. In a device of the character described the combination comprising; an electromagnet having a pair of individually energizable coil windings arranged to provide the electromagnet with a bore that has an open and closed end, a plunger slidable in said bore and adapted to be moved by magnetic attraction to one predetermined position in said bore and positively limited in its movement in one direction by the closed end of said bore when one of said coils is energized, an armature slidably mounted on said plunger exterior to said electromagnet and arranged to move said plunger to a second predetermined position and engage said electromagnet when the other coil is energized, and spring means for moving said plunger to a third predetermined position when both of said coils are de-energized.

6. In a device of the character described, the combination comprising; a pair of longitudinally spaced coil windings adapted to be circuited to be individually energized and arranged about a common bore, said bore having a closed and an open end, a plunger movable by magnetic attraction in said bore in a first direction when either of said coil windings is energized and adapted to engage the closed end of said bore to positively limit the movement of said plunger in said first direction when one of said coils is energized, an armature slidable on said plunger adapted to engage the core adjacent the open end of said bore to move and positively limit the movement of said plunger when said other coil is energized, a spring means arranged to oppose relative movement between said armature and plunger in said first direction and a spring means between said open end and plunger for positively limiting the movement of said plunger in an opposite direction from said first direction when neither coil is energized.

7. A solenoid assembly comprising, a frame formed of magnetic material having a bore that has a closed end and an open end, a pair of coils in said frame spaced along the length thereof and encircling said bore, a support secured to one end of said frame and having an opening in alignment with the open end of said frame, a plunger movable in said bore by magnetic attraction and located within both of said coils in one position thereof and having a portion extending through the opening in said support, a first compression spring located between said support and said plunger for biasing said plunger to a first position, an armature slidably supported on a reduced portion of said plunger and engaging a larger diameter portion of said plunger to move the plunger toward the closed end of the frame when one of said coils is energized to attract said armature, a spring retainer member secured to said plunger and engaging said support when said first spring is holding said plunger in said first position, and a second spring interposed between said armature and said spring retainer member.

8. A three-position solenoid comprising, a frame, first and second axially aligned coils supported by said frame and having a bore that is closed at one end, a plunger slidable in said bore and movable by magnetic attraction, a first compression spring located between said frame and plunger and continuously biasing said plunger for movement toward a first position and holding said plunger 6 in said first position when said coils are de-energized, an armature slidably mounted on said plunger and engaging a portion of said plunger to move the plunger against the bias of said first compression spring to a second position wherein said armature engages said frame when said first coil is energized to attract said armature, a spring retainer fixed to said plunger for limiting movement of said plunger past said first position under the influence of said first spring, and a second compression spring interposed between said spring retainer and said armature, said second spring holding said armature against the said portion of said plunger and said first and second springs both being compressed when said plunger is moved to a third position wherein the end of said plunger contacts the closed end of said bore when said second coil is energized.

References Cited in the file of this patent UNITED STATES PATENTS 506,282 Timmis Oct. 10, 1893 2,292,478 Ray Aug. 11, 1942 2,292,736 Betz Aug. 11, 1942 2,344,178 Sparrow Mar. 14, 1944 2,533,187 Cataldo Dec. 5, 1950 

